RESEARCH AREAS

Oleg Poleuktov

Oleg Poleuktov Chemical Sciences and Engineering Division Argonne National Laboratory P: 630-252-3546 E: oleg@anl.gov   M.S., Moscow Institute of Physics and Technology, 1980; Ph.D., Moscow Institute of Physics and Technology, 1983

Biographical Sketch

• 2000-present: Chemist, Chemistry Division, Argonne National Laboratory
• 1999: Visiting Scientist, Chemistry Division, Argonne National Laboratory
• 1997-1998: Visiting Scientist, Chemistry Division, Argonne National Laboratory
• 1991-1996: Visiting Scientist, Department of Physics, Leiden University, The Netherlands
• 1989-2000: Senior Scientist, Institute of Chemical Physics, Russian Academy of Sciences, Moscow
• 1983-1989: Scientist, Institute of Chemical Physics, Russian Academy of Sciences, Moscow

Research Statement

Natural photosynthetic conversion of solar energy to chemical energy is a unique phenomenon which sustains life on Earth.  The key step of photosynthetic energy conversion involves rapid, photoinduced sequential electron transfers resulting in efficient charge separation across a biological membrane. Fundamental to fully understanding these electron transfer events is discerning the involvement of heterogeneous polypeptide environments surrounding the redox cofactor sites.  High-resolution X-ray crystal structures of reaction center (RC) proteins reveal the structure of cofactors and surrounding protein environments, however, static crystallographic protein structures do not readily yield details of how native dynamic solution protein structures fine-tune electron transfer processes and coupled reactions, such as proton transfer.  Thus, novel approaches complementary to crystallography are required to experimentally correlate structural, electrostatic, and dynamic features of localized protein environments with inherent electron transfer reactions.

In our research we utilize a suite of advanced, multi-frequency, time-resolved EPR resonance techniques in combination with specialized samples. The center piece of these advanced techniques is high-frequency, pulsed, 130 GHz EPR spectroscopy which demonstrates a unique high absolute sensitivity and high spectral resolution compared to conventional 9 GHz EPR spectroscopy.

The ultimate goal of our photosynthetic research is to obtain fundamental knowledge of how photochemical processes at the molecular level are linked to the chemistry of macroscopic energy conversion. Specifically our research related to the protein’s role in controlling and defining optimal pathways for ET reactions; the response of the protein to rapid charge transfer and separation; and local metal and cofactor site structure related to conformationally gated ET.  This knowledge is crucial for the future design and optimization of novel biomimetic and model artificial solar energy conversion systems.

Publications

• "Electronic Structure of the P700 Special Pair from High-Frequency Electron Paramagnetic Resonance Spectroscopy," Poluektov, O. G., Utschig, L. M., Schlesselman, S. L., Lakshmi, K. V., Brudvig, G. W., Kothe, G., and Thurnauer, M. C.  J. Phys. Chem. B 106, 8911-8916 (2002).
• "Substrate-supported Lipid Nanotube Arrays," Smirnov, A. I. and Poluektov, O. G. J. Am. Chem. Soc. 125, 8434-8435 (2003).
• "Time-Resolved High-Frequency and Multifrequency EPR Studies of Spin-Correlated Radical Pairs in Photosynthetic Reaction Center Proteins," Thurnauer, M.C., Poluektov, O.G., and Kothe, G. Chapter 6 in Biological Magnetic Resonance, Volume 22, Very High Frequency (VHF) ESR/EPR, Kluwer Academic, Plenum Publishers, New York, Eds. Grinberg, O.Y., Berliner, L.J., 165-206 (2004).
• "ENDOR of Spin-Correlated Radical Pairs in Photosynthesis at High Magnetic Field: A Tool for Mapping Electron Transfer Pathways," Poluektov, O. G., Utschig, L. M., Dubinskiy, A. A., and Thurnauer, M. C. J. Am. Chem. Soc. 126, 1644-1645 (2004).
• "Photoinitiated Charge Separation: from Photosynthesis to Nanoparticles," Thurnauer, M. C., Dimitrijevic, N. M., Poluektov O. G., and Rajh, T. The Spectrum 17, 10-15 (2004).
• "Bidirectional Electron Transfer in Photosystem I:  Direct Evidence from High-Frequency Time-Resolved EPR," Poluektov, O. G., Paschenko, S. V., Utschig, L. M., Lakshmi, K. V., and Thurnauer, M. C.  J. Am. Chem. Soc. 127, 11910-11911 (2005).
• "Geometry of Hydrogen Bonds Formed by Lipid Bilayer Nitroxide Probes:  A High Frequency Pulsed ENDOR/EPR Study," Smirnova, T. I., Smirnov, A. I., Pachtchenko, S., and Poluektov, O. G.  J. Am. Chem. Soc. 129, 3476-3477 (2007).
• "Electron Transfer Pathways and Protein Response to Charge Separation in Photosynthetic Reaction Centers:  Time-Resolved High-Field ENDOR of the Spin-Correlated Radical Pair P865+QA-," Poluektov, O. G., Utschig, L. M., Dubinskij, A. A., and Thurnauer, M. C. J. Am. Chem. Soc. 127, 4049-4059 (2005).